Vehicles, such as cars are often provided with one or more rear windscreen wipers that can be switched on and off by the driver of the vehicle. Current rear windscreen wipers are operated using a manual control switch that is typically positioned on a control stalk located close to the steering wheel. Current windscreen wiper control switches allow for the rear windscreen wiper to operate in: an intermittent on mode; or an off mode.
The frequency of operation of the rear windscreen wiper may be a pre-programmed frequency that is the same irrespective of vehicle circumstance. Alternatively, the frequency of operation of the rear windscreen wiper may be determined in dependence upon the drive speed of the vehicle, such that with increasing vehicle drive speed, the rear wiper is activated more frequently. In current wiper systems, the speed at which the wiper moves across the rear windscreen is typically maintained at the same value irrespective of the frequency with which the wiper is activated.
A problem that is encountered with current rear wiper systems is that, when a driver decides to observe the environment behind the vehicle by looking through the rear windscreen, (typically using a rear-view mirror), the rear windscreen may not be wiped and may be obscured despite the rear windscreen wiper having been switched on normally by the driver. This is because the timing of the driver looking through the rear-windscreen may be in between wipes of the rear windscreen the two being entirely independent of each other. This can be disadvantageous and often leads to the driver manually adjusting the wiper control switch on the control stalk to initiate a single wipe. Whilst the driver then knows that the rear windscreen has just been cleared and the driver can then observe the environment behind the vehicle, a delay has been incurred which may be disadvantageous. Additionally to operate the control switch the driver may have looked down. Whilst this may only have been a momentary action it would be preferred if the driver did not have to take such action. This is especially so in rainy conditions where screen wipers are required. Furthermore, the driver may have to repeatedly make the effort to “manually” cause the wipers to clear the rear windscreen as the vehicle is driven in rainy conditions.
It is against this background that the present invention has been conceived. Embodiments of the invention may provide an improvement in the field of windscreen wiper systems, more specifically but not exclusively, in the field of rear windscreen wiper systems. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.